Comparisons of the Therapeutics for Diabetic Neuropathic Pain: Prospective Cohort Study, Seoul, Korea

Category: Diabetes; Other Introduction/Purpose: Treating chronic diabetic peripheral neuropathic pain poses significant clinical challenges due to variable outcomes and failed trials, along with the difficulty in objectively evaluating improvement and accounting for confounding factors. This study aims to investigate the treatment outcomes of three drugs (pregabalin, gabapentin, duloxetine) for chronic diabetic peripheral neuropathy. Methods: From June 2019 to June 2021, 180 patients with type 2 diabetes diagnosed with diabetic peripheral neuropathic pain received treatment with pregabalin, gabapentin, or duloxetine. The study protocol was approved by the institution’s IRB. Patients were consented and enrolled in a single Korean - center, prospective, randomized cohort study with 60 participants per drug group. Treatment lasted for 3 months, and participants were randomly assigned to groups at a 1:1:1 ratio using 3-multiple block randomization. Group 1 received Gabapentin (300mg bid), Group 2 received Pregabalin (75mg bidX mg ), and Group 3 received Duloxetine (30mg bid PO daily). Efficacy and safety were assessed every 2 weeks over a 6-week period. Baseline assessments included lipidemia profile, blood viscosity tests, BUN/Cr, OT/PT, and HbA1c. Clinical evaluations were performed using the Korean version of pain DETECT, categorizing degrees of improvement. Results: All treatments significantly improved painDETECT scores at 6 weeks of medication compared to their baseline (p=0.001). The mean HbA1c of the three groups showing symptomatic improvement by more than 50% was 9.424 (95% CI, 8.17-10.68) for Group 1, 10.430 (95% CI, 8.65-12.21) for Group 2, and 7.718 (95% CI, 6.74-8.70) for Group 3. There was no significant difference in HbA1c between Groups 1 and 2 regarding symptom improvement by more than 50%. However, the HbA1c of Group 3 was significantly lower than that of Groups 1 and 2 (p=0.001). Improvement of the symptom over 50% varied with HbA1c levels among three groups (p=0.001) . Adverse effects such as dizziness and nausea were significantly higher in the duloxetine group compared to pregabalin and gabapentin groups (p=0.001). Conclusion: All three medications effectively alleviated chronic diabetic peripheral neuropathic pain compared to their baseline level with no difference between the groups. However, HbA1c levels could be considered when selecting drugs because the HbA1c level when symptoms improve is different between the gabapentin, pregabalin, and duloxetine groups. There was no significant difference in the improvement of painDETECT scores in the three treatment groups up to the second week. However, by the sixth week, the pregabalin and duloxetine groups exhibited significantly more improvement in painDETECT scores than the gabapentin group (p=0.001).